How Jupiter got its stripes
Posted: Sun Mar 09, 2003 3:33 pm
Thirty years after the first mission to Jupiter, new images of the largest planet in our solar system have overturned the accepted explanation of how it got its stripes.
Pictures taken by the Cassini space probe revise long-held beliefs about its darker belts and lighter zones, said Carl Murray of the Astronomy Unit at Queen Mary, University of London, one of the team that report the analysis of the images in the journal Science.
Stripes dominate Jupiter's appearance. Darker ''belts'' alternate with lighter ''zones.'' Scientists have long considered the zones, with their pale clouds, to be areas of upwelling atmosphere, partly because many clouds on Earth form where air is rising. On the principle of what goes up must come down, the dark belts have been viewed as areas where air generally descends.
The Cassini images reverse this, showing the belts as rising areas with the zones sinking.
The pictures clearly show Jupiter's famous Red Spot--a giant atmospheric storm as wide as two Earths and more than 300 years old, with winds of 300 mph.
One of Jupiter's moons, Io, can also be seen, looking like a tiny pea next to the planet.
Analysis of Jupiter's moons--now numbering 47--includes evidence that two of the smaller moons, Metis and Adrastea, supply material for the planet's rings.
Cassini, built by NASA, was launched in 1997 on a mission to Saturn, which it should reach in July 2004. It carries the European Space Agency's Huygens probe, which is due to parachute into the atmosphere of Saturn's moon Titan.
Pictures taken by the Cassini space probe revise long-held beliefs about its darker belts and lighter zones, said Carl Murray of the Astronomy Unit at Queen Mary, University of London, one of the team that report the analysis of the images in the journal Science.
Stripes dominate Jupiter's appearance. Darker ''belts'' alternate with lighter ''zones.'' Scientists have long considered the zones, with their pale clouds, to be areas of upwelling atmosphere, partly because many clouds on Earth form where air is rising. On the principle of what goes up must come down, the dark belts have been viewed as areas where air generally descends.
The Cassini images reverse this, showing the belts as rising areas with the zones sinking.
The pictures clearly show Jupiter's famous Red Spot--a giant atmospheric storm as wide as two Earths and more than 300 years old, with winds of 300 mph.
One of Jupiter's moons, Io, can also be seen, looking like a tiny pea next to the planet.
Analysis of Jupiter's moons--now numbering 47--includes evidence that two of the smaller moons, Metis and Adrastea, supply material for the planet's rings.
Cassini, built by NASA, was launched in 1997 on a mission to Saturn, which it should reach in July 2004. It carries the European Space Agency's Huygens probe, which is due to parachute into the atmosphere of Saturn's moon Titan.
